1. Field of the Invention
This invention relates to a process for producing a bakery product having a layered structure, such as Danish pastry, croissant or pie.
2. Description of the Prior Art
Bakery products having a layered structure containing a roll-in fat may be broadly classified into those produced by using yeast, such as Danish pastry and croissant, and those produced without using yeast, such as pie. Each of these bakery products may be produced by sheeting and folding a dough, which has been prepared by kneading a mixture comprising, for example, wheat flour, salt, sugar and water, together with a plastic fat such as butter or margarine several times, allowing the layered dough thus obtained for an appropriate retarding time, then subjecting it to the final sheeting, stamping out a suitable shape from the dough, molding it into a desired shape, effecting the final proofing, which is unnecessary in the case of a pie, and then baking.
There has been attempted, in the main, to develop a fat which is highly spreadable over a wide temperature range and has a high consistency, in order to form excellent flaky layers in the inner phase of the final bakery product produced by the aforesaid process. This is because the fat to be rolled in the dough should have a high spreadability suited to the dough. When the fat to be rolled in the dough is excessively hard, not only the obtained final product has a poor flavor, but also the fat cannot be distributed into the whole dough and any homogeneous product cannot be obtained from the non-uniform dough thus formed. When the fat is excessively soft, on the contrary, it would lose the shape retentiveness during the roll-in procedure. Thus it would run or be incorporated in the dough, which makes the processability poor. As a result, the final product has scarcely any flaky layer. In order to prevent these phenomena, it is a common practice to refrigerate the fat one or several times during the roll-in process so as to prevent the softening of the fat and to restore the working properties of the wheat flour dough, thus adjusting the spreadability of the dough and that of the fat. Therefore it has been required to develop a fat, which has a good spreadability within a low temperature range, to be used in the aforesaid process for producing bakery products. Thus it has been proposed to add a thickener to the aqueous phase of an water-in-oil emulsion fat (refer to Japanese Patent Laid-Open No. 11141/1984), to blend glyceryl monoacetate with the aqueous phase of a water-in-oil emulsion fat (refer to Japanese Patent Publication No. 35739/1987) and to restrict the fatty acid composition of a fat (refer to Japanese Patent Laid-Open No. 22133/1985) to thereby improve the spreadability of a fat.
Recently, however, consumers have a marked trend toward fat-free foods for the reason of health and thus the consumption of fat-rich products such as Danish pastry, croissant or pie has been stagnant. When it is attempted to produce a low-fat product (i.e., one containing less roll-in fat), the roll-in fat is incorporated into the dough layer 2, due to the good spreadability of the fat, during the roll-in or final sheeting operation, so that the fat layer 1 becomes very thin or disappears (refer to FIG. 2). As a result, the final product has no layered structure but an inner phase of a so-called bread-like (sponge) texture just like that of a butter roll, which deteriorates the texture and voluminousness of the product.
In order to prevent these phenomena, Japanese Patent Laid-Open No. 202245/1989 proposes the use of a fat which has a high protein concentration and is in the form of a stable oil-in-water emulsion. However this method has some disadvantages, for example, the oil-in-water fat results in poor keeping qualities and it is necessary to add a sizing agent to the aqueous phase, which makes the texture poor.
A conventional bakery product rich in a roll-in fat has a layered structure consisting of a fat layer 1 and a dough layer 2, as shown in FIG. 3.